Study on Calculating Formula of Pile-soil stress Ratio of CFG Pile-raft Composite Foundation

The deformation performance of CFG pile composite foundation under loading was discussed,and the relationship between the pile lateral friction and the piles-soil relative deformation was studied. By adopting the concept of the equal settlement section,the piles and the surrounding soil were assumed to be linear elastic masses,and the distributions of pile lateral frictions were assumed to be linear.On the basis of the deformation coordination condition of pile-soil-cushion and the load transfer method,a calculating formula of the pile-soil stress ratio of CFG pile-raft composite foundation was proposed. And the equations are used to analyze the practical project; the result calculated by the proposed formula is close to the result of test and the result of FEM.